When using corrugated polyethylene drainage pipes buried over extended lengths, it is necessary to couple the ends of adjacent sections of the pipes. The connected lengths of pipe are fed through a trenching machine as disclosed in my U.S. Pat. No. 4,871,281. It is imperative that any coupling device used between lengths of pipe have a smooth exterior to avoid "hang-up" of the pipe as it is fed into a trench through guide openings.
It may also be necessary to join one end of a section of corrugated drainage pipe to vertical PVC headers, pipes, pump sections and discharge pipes. Due to the polyethylene composition of the corrugated drainage pipe, it is not readily possible to achieve a bond with adjacent PVC pipe sections through commercially available adhesives.
Examples of plastic pipe couplings are found in U.S. Pat. No. 4,084,844 to Abner, U.S. Pat. No. 4,871,198 to Hattori et al., U.S. Pat. No. 4,760,622 to Pate et al., U.S. Pat. No. 4,443,031 to Borsh et al., and U.S. Pat. No. 4,795,197 to Kaminski et al.
U.S. Pat. No. 4,084,844 to Abner discloses a device for connecting corrugated drainage tiles. The device is a flexible sleeve which is held together and in place against linear movement by special "tabs", which not only close adjacent sections of drainage tile, but when the sleeve is overlapped upon itself, the tabs penetrate exterior grooves to hold the linear position of the device. This device cannot be used as a coupling for feeding through a trenching tool without "hang-ups" due to its overlapped edges or as an adapter to smooth bore pipes due to its overlapped portions forming an asymmetrical configuration. Further, the sleeve is not made of materials suitable for adapting polyethylene materials to polyvinyl chloride pipe.
U.S. Pat. No. 4,871,198 to Hattori et al. discloses a clamp-type corrugated plastic type coupling which is clamped with a split mold having flanges. The coupling includes an outer coupling member having corrugations along its inner surface and a packing member arranged inside the outer coupling member. This coupling is a special pressure type coupling particularly for underground electrical conduits and sewage pipe installations which require extreme water tightness. The clamping flanges and external components preclude the implementation of this device as a coupler for feeding through a trenching tool without "hang-ups" or as an adapter to smooth bore pipes, fittings, or other receptacles.
U.S. Pat. No. 4,470,622 to Pate et al. discloses a system of flexible conduit and fittings useful particularly for conveying, supporting and connecting electrical service cables and wires. The conduit and fittings are made of polyvinyl chloride and due to the exterior configuration of the fittings implementation as a coupler for feeding through a trenching tool without "hang-ups" or as an adapter to smooth bore pipes, fittings or other receptacles is infeasible.
U.S. Pat. No. 4,443,031 to Borsh et al. discloses a connector fitting for interconnecting flexible corrugated conduit sections which includes a pair of arcuate sections joined by flexible straps having corrugation engaging ribs. This device relates to joining or coupling a pair of flexible corrugated conduit sections of the type used as a raceway for electrical conductors. The corrugated conduit sections are connected end to end with external bands which project well beyond the periphery of the connector fitting. A strong conduit connector for electrical raceways results which is incapable of serving as a coupler for feeding through a trenching tool without "hang-ups" or as an adapter to smooth bore pipes, fittings or other receptacles.
U.S. Pat. No. 4,795,197 to Kaminski et al. discloses a coupling for seed and fertilizer hoses. Two portions are molded as a single unit with an integral hinge and locking structure located on the periphery of the coupling. The peripheral structure precludes the use of this coupling as a coupler for feeding through a trenching tool without "hang-ups" or as an adapter to smooth bore pipes, fittings or other receptacles.